The drug discovery process is currently undergoing a fundamental revolution as it embraces `functional genomics`, that is, high throughput genome- or gene-based biology. This approach is rapidly superceding earlier approaches based on `positional cloning`. A phenotype, that is a biological function or genetic disease, would be identified and this would then be tracked back to the responsible gene, based on its genetic map position.
Functional genomics relies heavily on the various tools of bioinformatics to identify gene sequences of potential interest from the many molecular biology databases now available. There is a continuing need to identify and characterise further genes and their related polypeptides/proteins, as targets for drug discovery.
Cytokines are small secreted proteins which bind to their receptors on the cell membrane and regulate many important cellular processes such as cell growth and differentiation. The amino acid sequence of these cytokines usually do not have significant homology between different subfamilies due to the diversity of the functions. However, we identified a four helix bundle structure which was conserved among a variety of cytokines including erythropoietin and growth hormone. Using a structure-based genomics approach, we have identified a novel family of four highly homologous genes which are structural homologues of erythropoeitin and growth hormone.